This invention relates to guyline insulators and particularly to guyline insulators for VLF antennas.
Guyline insulators currently in use in VLF antennas are made from ceramic-type materials, good insulators but very rigid. Their rigidity makes these insulators highly susceptible to brittle failures, and, therefore, to provide the required physical strength, these insulators are made physically large and very heavy. The result is that they each weigh on the order of several thousand pounds. This tremendous bulk and weight are the major disadvantages of present guyline insulators, which makes the handling, installation and maintenance very difficult and costly.
These insulators are also susceptible to breakdown caused by excessive high voltages which results from lightning or other electrical disturbances. To provide the necessary electrical insulation for high voltage protection, several of these prior type insulators must be connected in series. This, however, only compounds the major disadvantage of the guyline insulator. The tremendous added weight must be supported by the antenna and its guylines, which requires added cost for a stronger antenna structure. Also the added mechanical stresses lead to the increased probability of physical breakdown in both the antenna and guyline insulators.
Various attempts have been made to overcome these problems, but have not resulted in a satisfactory VLF guyline insulator. A variety of techniques have been used, each of which has been lacking in several critical areas.
In an effort to alleviate the prior art problems, the modular guyline insulator of the present invention has been developed. The present invention utilizes light-weight, high tensile strength materials to provide the physical strength at a fraction of the size and weight of prior type ceramic insulators. The present device also provides high voltage protection by the use of toroidal corona rings which force high voltage arcs to occur through the atmosphere rather than through the insulator. As an added feature, the modular guyline insulator provides an indication of possible failure of the insulator before failure occurs. This is a very desirable feature not only from the standpoint of maintenance, but from the resulting increased reliability of the system. Guylines are used on many antennas for structural support. To prevent the grounding of the antennas, guyline insulators are used. These guyline insulators must have high tensile strength and still provide good insulation at high voltages. The modular guyline insulator of the invention meets all of these requirements.